1. Field of the Invention
The present invention relates to a process for preparation of a fatty acid ester with remarkably good productivity (hereinafter referred to as space time yield) by reacting a lower fatty acid and a lower olefin.
2. Description of the Related Art
In the past, as a process for preparation of such an ester by reaction of a lower fatty acid with a lower olefin, there has been known the process, as disclosed in Japanese Examined Patent Publication (Kokoku) No. 53-6131, of using as a catalyst sulfuric acid, phosphoric acid, or other mineral acid, phosphotungstic acid, phosphomolybdic acid, or other heteropoly-acids. Further, Japanese Examined Patent Publication (Kokoku) No. 47-42808 and Japanese Examined Patent Publication (Kokoku) No. 56-30334 disclose processes for a reaction in the liquid phase using as a catalyst phosphotungstic acid, phosphomolybdic acid, or other heteropoly-acid or an acid metal salt of phosphotungstic acid or silicotungstic acid.
In these conventional processes using a catalyst, however, the space time yield was low and the life of the catalyst was short, so the production process was far from being of industrial use.